I agree about the lanes - it's very difficult, especially when some people (quite reasonably I guess) stand around in the slow lane, forcing the people that are slow but want a proper swim, into the medium lane, which in turn forces the medium-speed swimmers into the fast lane. The problem seems to be worse in the women's only session; I'm afraid I ended up swimming in the fast lane myself last week when I didn't really have any business being there simply because it was so frustrating in the medium lane (although to be fair the very speedy people could overtake). Once the AquaAerobics session started, though, taking over half the pool lengthways, the situation degenerated completely, creating what I can only describe as a very turbulent soup of mixed-ability swimmers, at which point I had to get out. I wonder if AquaAerobics doesn't really combine well with ordinary or women's only sessions, certainly not without substantially reducing the number of people in the pool. I totally agree with the above poster who suggested more active supervision of lanes.